LUCY® Stains

Three fluorescent protein stains, LUCY-506, LUCY-565 and LUCY-569 have been developed. These dyes are suitable for staining proteins on polyacrylamide gels (both 1D- and 2D-Electrophoresis) and offer a reliable, convenient and economic alternative to current silver staining techniques or existing fluorescent staining methods for the detection of minute amounts of protein.

In general the staining procedures are easy, fast and robust. The standard procedure is a post-electrophoretic stain without fixation-step, which is completed after 60min. Using a modified staining protocol, it is also possible to stain a gel with LUCY-565 and perform a western-blot afterwards. Native gels can be visualized by rinsing the gel in SDS immediately after the run, but before staining it. Table 1 summarizes the suitability and performance of these dyes for different staining procedures.

Several devices can be used for the detection, e.g. illuminating the gel on a transilluminator (Dark-Reader, UV-Screen) and imaging the gel using a CCD- or Polaroid-Camera. Alternatively a laser scanner can be employed, using the corresponding excitation and filter settings. Table 2 shows an overview over the applicable systems for illumination.

The profile of each of the dyes has been established: LUCY-506 shows the highest sensitivity, LUCY-565 allows neutral staining (e.g. before Western blotting) and LUCY-569 excels by a linear response over an extraordinary broad linear dynamic range.

The detection limits for the 3 dyes ranged between 3-10 ng/band in 1D-PAGE. Fig.1 shows a comparison between LUCY-506 and Sypro Ruby in 2D electrophoresis. Comparisons to current state-of-the-art dyes were drawn under different experimental conditions. In-gel digested proteins can be analysed by mass spectrometry

Linearity

LUCY dyes generally provide a large range of linearity. Linearity was given up to 1000-6000 ng/band and is therefore larger than for silver stains (White et al., Electrophoresis 2004; 25(17); 3048-3054), coomassie blue or other fluorescence dyes.

Figure 2: Dynamic range of LUCY stains in comparison to other staining methods.